McDermott guided the Royals into the Barclays Premier League for only the second time in their history last season but they have struggled for form and now sit 19th, with only goals scored keeping them ahead of bottom side QPR.
Former Swindon boss and Celtic player Paolo Di Canio has been installed as the early bookmakers' favourite and was amongst the crowd for the Royals' 2-1 loss to Villa on Saturday, which proved to be McDermott's last game in charge of the club he has worked for in a number of roles since 2000.
Zingarevich had consistently backed McDermott in public and the former Arsenal midfielder collected the Barclays Premier League manager of the month award in January after a run of one defeat in seven games for the Berkshire club.
Reading released a statement yesterday afternoon announcing the decision and said the process to appoint a replacement was already under way.
"Brian gained promotion to the Barclays Premier League last year for only the second time in the club's history thanks to a remarkable run at the end of last season," the statement read.
"However, in our current situation, owner Anton Zingarevich felt that a change was necessary.
"The search for a successor will start immediately and it is hoped that a new manager will be in place as soon as possible to lead the fight against potential relegation."
The club later announced that Academy head Eamonn Dolan would take charge of first-team matters going into the upcoming match against Manchester United.
The Royals also confirmed that first-team coach Nigel Gibbs had left the club he joined in 2006.
McDermott paid the price for back-to-back home defeats against fellow strugglers Wigan and Aston Villa but experienced striker Jason Roberts was quick to thank McDermott for his work at the Madejski Stadium.
"He's a football man and a good man and I just think at this moment in time we take stock of what he has achieved and place on record our thanks," he told Sky Sports News.
"I as an individual player and I'm sure the others would like to place on record their thanks for what he and his (backroom) team have achieved for us."
Fellow forward Noel Hunt took to Twitter to praise the out-going boss, Tweeting: "Want to say thanks to Brian for everything he did for me especially. He's been a Great Manager, Man and Friend to me and will be missed!"
With away games at Manchester United and Arsenal the next two fixtures for Reading it remains to be seen if a replacement will be appointed before the trip to Old Trafford on Saturday evening.